Robot

Abstract

A robot, comprising: a first component (20); a second component (30) that is rotationally driven relative to the first component (20) about a specified axis (J2), including a pair of flange portions (31) arranged at intervals in the direction of the axis (J2), and being supported by the first component (20) via each flange portion (31) so as to be rotatable about the axis (J2); a balancer (60) that is mounted on the first component (20) and the second component (30) so as to be rotatable about mounting axes (J11), (J12) parallel to the axis (J2) respectively; and an adapter (70) that is inserted between the pair of flange portions (31), is detachably mounted on the second component (30), and has the mounting axis (J12) of the balancer (60) relative to the second component (30) arranged at a position radially inside the outer peripheral surface of the flange portion (31) and eccentric with respect to the axis (J2).

Description

Technical Field

[0001] The present invention relates to a robot. Background Art

[0002] A known robot rotates a first arm driven by a motor relative to a rotating body about a horizontal rotation axis, and includes a balancer that reduces the load torque acting on the motor by the elastic force of a compression coil spring (for example, refer to Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-188513 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In order to further increase the auxiliary torque generated by the balancer, the mounting position of the balancer on the first arm is made significantly eccentric with respect to the rotation axis. In this case, the stroke of the balancer corresponding to the movement range of the first arm becomes large. In order to increase the stroke of the balancer, it is necessary to increase the number of turns of the compression coil spring. However, if the number of turns is increased, the overall length of the balancer becomes long, and the rigidity of the compression coil spring decreases.

[0008] In order to increase the rigidity while suppressing the stress of the wire material of the compression coil spring within the allowable range, it is necessary to increase the wire diameter and outer diameter of the compression coil spring, which results in the enlargement of the balancer.

[0009] Therefore, it is desired to prevent the enlargement of the balancer and generate a larger auxiliary torque.

[0010] Means for Solving the Problems

[0011] One aspect of the present invention is a robot including: a first component; a second component that is rotationally driven relative to the first component about a predetermined axis, includes a pair of flange portions arranged at intervals in the axial direction of the axis, and is supported by the first component in a rotatable manner about the axis through each of the flange portions; a balancer that is mounted on the first component and the second component in a rotatable manner about a mounting axis parallel to the axis; and an adapter that is inserted between the pair of flange portions, is detachably mounted on the second component, and has the mounting axis of the balancer relative to the second component disposed at a position radially inward of the outer peripheral surface of the flange portion and eccentric with respect to the axis. Brief Description of the Drawings

[0012] Figure 1It is an overall structure diagram of a robot according to an embodiment of the present invention.

[0013] Figure 2 It is Figure 1 an exploded view of the first arm and the adapter of the robot.

[0014] Figure 3 It is Figure 1 a schematic cross-sectional view of the balancer of the robot.

[0015] Figure 4 It is Figure 1 a schematic diagram showing the state of the vertical posture of the first arm in the robot.

[0016] Figure 5 It is Figure 1 a schematic diagram showing the state where the first arm is tilted in the robot.

[0017] Figure 6 It is Figure 1 a modified example of the robot, which is a partially enlarged view showing the installation state of the first arm and the adapter. Detailed Description of the Invention

[0018] Hereinafter, a robot 1 according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0019] As Figure 1 shown, the robot 1 according to the present embodiment includes: a base 10 provided on the ground; and a rotating body (first component) 20 supported so as to be rotatable relative to the base 10 about a first axis J1 extending in the vertical direction.

[0020] The robot 1 includes: a first arm (second component) 30 supported so as to be rotatable relative to the rotating body 20 about a second axis (axis) J2 extending in the horizontal direction; and a second arm 40 supported so as to be rotatable relative to the first arm 30 about a third axis J3 parallel to the second axis J2. In addition, the robot 1 includes: a 3-axis wrist unit 50 mounted at the front end of the second arm 40; a balancer 60 disposed between the rotating body 20 and the first arm 30; and an adapter 70 for detachably mounting the balancer 60 to the first arm 30.

[0021] A pair of disk-shaped flange portions 31 are integrally provided at the base end of the first arm 30, and the pair of disk-shaped flange portions 31 are arranged at intervals in the direction along the second axis J2 and extend in a direction orthogonal to the second axis J2.

[0022] A pair of support portions 21 are provided on the rotating body 20, and the pair of support portions 21 are arranged at positions sandwiching the pair of flange portions 31 of the first arm 30 from the outside in the direction along the second axis J2.

[0023] A speed reducer 34 is disposed between each flange portion 31 and each support portion 21. A motor 35 is fixed to one support portion 21, and the rotation of a motor shaft (not shown) is input to both of the pair of speed reducers 34. The two speed reducers 34 reduce the rotation of the motor shaft at the same reduction ratio and transmit it to each flange portion 31. Thus, the first arm 30 rotates around the second axis J2 with respect to the rotating body 20, and the load torque acting on the first arm 30 is shared and borne by the two speed reducers 34.

[0024] As Figure 2 shown, a seating surface 32 is provided on the outer peripheral surface of each flange portion 31, and the seating surface 32 is disposed on the side of the balancer 60 in a state where the first arm 30 is disposed in the vertical direction. A plurality of threaded holes for fixing an adapter 70 described later are provided in each seating surface 32.

[0025] As Figure 3 shown, the balancer 60 includes: a housing 61, a disk-shaped movable member 62 accommodated in the housing 61 so as to be movable in the direction of the long axis OL1, a long rod 63, and a compression coil spring 64.

[0026] The housing 61 includes a cylindrical main body portion 61a and end plates 61b, 61c that respectively close both ends of the main body portion 61a in the direction of the long axis OL1. A through hole 61h penetrating in the direction along the long axis OL1 of the main body portion 61a is provided at the center of one end plate 61b. The rod 63 penetrates through the through hole 61h so as to be movable in the direction of the long axis OL1.

[0027] One end of the rod 63 disposed in the housing 61 is fixed to the movable member 62, and a mounting block 66 is fixed to the other end of the rod 63 disposed outside the housing 61.

[0028] The compression coil spring 64 is accommodated in the housing 61 in a state of being sandwiched between the movable member 62 and the end plate 61b. Thus, the movable member 62 is pressed toward the end plate 61c side by the elastic restoring force of the compression coil spring 64, and the rod 63 is biased in the direction of being pulled into the housing 61.

[0029] On both sides in the diameter direction at an intermediate position, for example, the central position in the direction of the long axis OL1 on the main body portion 61a of the housing 61, first mounting holes 65 extending along an orthogonal axis OL2 orthogonal to the long axis OL1 are provided. A pair of first shafts 22 extending in the direction of a first mounting axis (mounting axis) J11 parallel to the second axis J2 are inserted into the respective first mounting holes 65.

[0030] The first shafts 22 are fixed to the rotating body 20. Thus, the balancer 60 is mounted on the rotating body 20 so as to be rotatable around the first mounting axis J11.

[0031] A second mounting hole 67 extending in a direction orthogonal to the long axis OL1 is provided in the mounting block 66.

[0032] As Figure 2 shown, the adapter 70 includes: a second shaft (axis) 71 rotatably fitted into the second mounting hole 67 of the mounting block 66; and a pair of substantially parallel strip-shaped support plates 72 supporting both ends of the second shaft 71. In addition, the adapter 70 includes a connecting portion 73 connecting one ends of the support plates 72 to each other; and a pair of fixing portions 74 extending from the other ends of the support plates 72 in a direction orthogonal to the support plates 72.

[0033] Through holes penetrating in the plate thickness direction are provided in the pair of support plates 72, and the second shaft 71 is detachably fixed in the direction penetrating these through holes.

[0034] By fixing the second shaft 71 fitted into the second mounting hole 67 of the mounting block 66 to the support plate 72, the adapter 70 is mounted to the front end of the rod 63. Then, the pair of support plates 72 having the second shaft 71 fixed thereto are inserted between the pair of flange portions 31, and bolts passing through the through holes of the fixing portions 74 of the adapter 70 are fastened to the threaded holes of the seat surface 32 of the first arm 30, whereby the adapter 70 is fixed to the first arm 30. Thus, the second shaft 71 is arranged at a position radially inward of the outer peripheral surface of the flange portion 31 along a second mounting axis (mounting axis) J12 parallel to the second axis J2, and the front end of the rod 63 of the balancer 60 can be rotatably mounted to the first arm 30 about the second mounting axis J12.

[0035] Hereinafter, the operation of the robot 1 according to the present embodiment configured as described above will be described.

[0036] In the robot 1 according to the present embodiment, for example, as Figure 4 shown, in a state where the first arm 30 extends in the vertical direction, the second mounting axis J1B is arranged in a plane including the first mounting axis J11 and the second axis J2.

[0037] That is, in this state, the protruding amount of the rod 63 from the housing 61 is the smallest, and the compression amount of the compression coil spring 64 is also the smallest. In addition, since the second mounting axis J12 is arranged in the plane including the second axis J2 and the first mounting axis J11, no auxiliary torque of the balancer 60 about the second axis J2 is generated.

[0038] From this state, by the operation of the motor 35, as Figure 5 shown, when the first arm 30 is rotated about the second axis J2, the inclination angle of the first arm 30 with respect to the vertical direction becomes larger, and the gravitational load torque acting on the first arm 30 increases.

[0039] Meanwhile, as the first arm 30 rotates, the second mounting axis J12, which is eccentric with respect to the second axis J2, moves away from the first mounting axis J11 around the second axis J2.

[0040] The balancer 60 rotates the housing 61 around the first mounting axis J11 corresponding to the movement of the second mounting axis J12 relative to the first mounting axis J11, and increases the protruding amount of the rod 63 from the housing 61. As a result, the compression amount of the compression coil spring 64 increases, and the force in the direction of pulling the rod 63 back into the housing 61 increases.

[0041] In addition, when the second mounting axis J12 deviates from the plane including the first mounting axis J11 and the second axis J2, an auxiliary torque obtained by multiplying the elastic force of the compression coil spring 64 by the length of the perpendicular line dropped from the second axis J2 to the long axis OL1 of the rod 63 acts in the direction opposite to the gravity load torque. The larger the inclination angle of the first arm 30 with respect to the plumb line, the larger the magnitude of the auxiliary torque.

[0042] In this case, in the robot 1 according to the present embodiment, by using the adapter 70, the second shaft 71 is disposed at a position radially inward of the outer peripheral surface of the flange portion 31. As a result, the eccentricity distance of the second mounting axis J12 with respect to the second axis J2 can be sufficiently reduced, and the stroke of the rod 63 corresponding to the movable range of the first arm 30 around the second axis J2 can be suppressed to be small.

[0043] That is, by suppressing the stroke of the rod 63 to be small, the overall length of the compression coil spring 64 can be shortened. As a result, the number of effective turns can be suppressed to be small, and high rigidity can be obtained without increasing the wire diameter and the outer diameter of the compression coil spring 64. As a result, there is an advantage that a larger auxiliary torque can be obtained while preventing the balancer 60 from becoming large.

[0044] In particular, even when a pair of speed reducers 34 are respectively mounted on a pair of flange portions 31, the second shaft 71 can be easily disposed at a position radially inward of the outer peripheral surface of the flange portion 31 through the adapter 70 from the direction intersecting the second axis J2. Moreover, by detachably mounting the adapter 70 on the first arm 30, there is also an advantage that the balancer 60 can be easily detached and attached to the first arm 30 without detaching the speed reducer 34 and the motor 35.

[0045] In addition, since the second shaft 71 is supported at both ends on a pair of flange portions 31 via a pair of support plates 72, even if the elastic force generated by the balancer 60 is increased, deformation of the second shaft 71 can be suppressed and it can be firmly supported.

[0046] In the present embodiment, the case where the first arm 30 is tilted in one direction (forward) has been described. However, the same applies to the case where it is tilted in the other direction (backward), and an auxiliary torque can be generated in the direction of reducing the gravity load torque.

[0047] In addition, the fixing portion 74 of the adapter 70 is fixed to the seating surface 32 provided on the outer peripheral surface of the flange portion 31 from the balancer 60 side. Thus, by fastening a bolt to the threaded hole of the seating surface 32, the adapter 70 can be fixed to the first arm 30 while applying an initial compression to the compression coil spring 64.

[0048] On the contrary, the fixing portion 74 may also be mounted on the seating surface 32 provided on the outer peripheral surface on the opposite side of the balancer 60 with the first arm 30 interposed therebetween.

[0049] In this case, for example, as Figure 6 shown, a flat fixing portion 74 that connects one ends of a pair of support plates 72 to each other may be provided.

[0050] Thus, the force that pulls the rod 63 toward the housing 61 side always presses the fixing portion 74 against the seating surface 32 of the first arm 30 via the second shaft 71. Therefore, the fastening force of the bolt that mounts the adapter 70 on the first arm 30 can be reduced.

[0051] Therefore, the size and the number of bolts used can be suppressed to be small, and miniaturization and weight reduction of the adapter 70 can be achieved.

[0052] In addition, in the present embodiment, a pair of speed reducers 34 are arranged at positions sandwiching the flange portion 31 from the outside. However, it is not limited thereto, and a single speed reducer 34 or three or more speed reducers 34 may be arranged.

[0053] Explanation of Reference Numerals

[0054] 1 Robot

[0055] 20 Rotating Body (First Component)

[0056] 30 First Arm (Second Component)

[0057] 31 Flange Portion

[0058] 60 Balancer

[0059] 64 Compression Coil Spring

[0060] 70 Adapter

[0061] 71 Second Shaft (Shaft)

[0062] 74 Fixing Portion

[0063] J11 First Mounting Axis (Mounting Axis)

[0064] J12 Second installation axis (installation axis)

[0065] J2 Second axis (axis)

Claims

1. A robot, characterized in that, Comprising: A first component; A second component, which is rotationally driven relative to the first component about a prescribed axis, includes a pair of flange portions arranged at intervals in the axial direction of the axis, and is supported by the first component in a manner capable of rotating about the axis through each of the flange portions; A balancer, which is mounted on the first component and the second component in a manner capable of rotating about a mounting axis parallel to the axis respectively; And An adapter, the adapter comprising: a pair of support plates, which can be inserted between the pair of flange portions; and a pair of fixing portions, which are detachably fixed to the respective outer peripheral surfaces of the flange portions; by fixing the pair of fixing portions to the respective outer peripheral surfaces, and arranging the mounting axis of the balancer relative to the second component at a position radially inward of the outer peripheral surface of the flange portion and eccentric with respect to the axis.

2. The robot according to claim 1, wherein The adapter is mounted on a part of the second component on the side opposite to the mounting axis of the first component across the axis.

3. The robot according to claim 1, characterized in that, The adapter includes: a shaft, the two ends of which are supported by the pair of fixing portions, and one end of the balancer is mounted to be capable of rotating about the mounting axis.

4. The robot according to any one of claims 1 to 3, characterized in that The balancer is a cylindrical balancer with a compression coil spring built therein.

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